Tab by Imogen13.

Just two chord formations, and she plays it the whole song. The formations are a lot
like playing an F chord (barred), but you take away your pinky finger, and move your
middle finger up one string, towards your ring finger. 

The video (at 6:30) - https://youtu.be/BJoOIlK3Vv0?t=390

Note: If you want to strum these as chords, make sure you mute/don't play the last 
three strings.

[Intro]

e|------------
B|------------
G|------------
D|---7----7---
A|---8----8---
E|-6----6----6

--------------
--------------
--------------
-7----7----7--
-8----8----8--
----6----6----

--------------
--------------
--------------
--7----7----7-
--8----8----8-
6----6----6---

|-------------
|-------------
|-------------
|---2----2----
|---3----3----
|-1----1----1-

--------------
--------------
--------------
2----2----2---
3----3----3---
---1----1----1

-------------|
-------------|
-------------|
-2----2----2-| x2
-3----3----3-|
----1----1---|

Very simple :)